Hose pipe



Patented Dec. 5, 1944 HOSE PIPE Bernard Wilkinson, London, England, asslgnor to Wilkinson Rubber Linatex Limited, London, England, a company of Great Britain Application November 9, 1942, Serial'No. 465,047 In Great Britain April 22, 1942 claims. (o1. 13s- 55) This invention relates to flexible hose pipes of the kind having a helical reinforcing winding. These hoses are generally made of rubber and embody a layer or layers of fabric where extra strength is necessary. The reinforcing winding, which serves to increase the flexibility of the hose and prevent it from kinking, is generally-of metal wire. Metal wire is however disadvantageous because Aof its resistance to deformation under small loads, which renders it difficult to fit` clips to the hose for securing it to a supporting fitting, and of its tendency to take a permanent set, as for example when the hose is accidentally trodden on, which may render the hose useless.

With a View to overcoming the disadvantages of the metal wire reinforcement, it has been proposed to substitute for it a helical winding of hard rubber. Hard rubber however softens at about 100 C. which means that a hose with a hard rubber reinforcing helix is of no use for conveying hot oil or steam, as the softening of the helix causes the hose to collapse when flexed.

The flexible hose pipe according to the invention is characterised by the incorporation therein of a helix-of regenerated cellulose embedded in the structure of the hose. This material` will stand fairly high temperatures of the order of 150 C. without undue softening or deterioration. Although regenerated cellulose will deform under small loads and so allow clips to be tted to the pipe, it does not easily take a permanent set, but regains its shape after sudden deformation.

The hose pipe may be constructed of rubber, either natural or synthetic, of a composition suited to the intended use of the hose. Thus, if the hose pipe is to be used for water or steam, it may be made of ordinary rubber (compounded to resist heat in the case of steam) whereas if it is to be used for carrying acids, it will be made of acid-resisting rubber. Again, if it is to be used for petrol or oil, it will be made of a petrol-resisting rubber or of e, synthetc rubber such as neoprene or the material hold under the British registered trade-mark Thiokol. The pipe may also be built up of flexible plastic materials, for example polyvinyl chloride. Layers of fabric may be included, on either side of the helix, or fabric may be introduced on both sides of the helix.

Where the pipe consists wholly or mainly of rubber, it is preferred to build up the pipe of uncured or partially cured rubber and to subject it to vulcanisation after completion, so as to ensure that the helix will become securely embedded in the rubber. With synthetic rubber or other plastic materials, a similar heat treatment after manufacture ls generally' desirable, to ensure embedding of the helix, setting o'f the joints, and curing of the materials. With plastic materials such as polyvinyl chloride, however, the heat treatment is not always necessary, and can be dispensed with if appropriate cements are used.

One form of pipe according to the invention may be constructed by mountinga rubber tube on a mandrel, then Winding regenerated cellulose wire around the rubber to form a helix (or slipping a preformed helix of regenerated cellulose wire over the rubber) then applying a layer of rubberised fabric, then applying an external layer of rubber, and finally vulcanising the pipe. As explained above, the fabric may be omitted altogether if desired, or alternatively a second layer of rubberised fabric may be applied inside `the helix. The outer ,layer of rubber may consist of a preformed tube or may be formed by wrapping rubber sheet around the partially completed structure on the mandrel.

Another form of pipe according to the invention consists of an inner tube of a flexible synthetic material, for example polyvinyl chloride, a surrounding layer of fabric having rubber on its outer surface, then a helix of regenerated cellulose, then a layer of fabric with rubber on the inside and finally an external layer of natural rubber, synthetic rubber or appropriate plastic material, the whole -being vulcanised after construction to embed the helix in the rubber carried on the layers of fabric.

If desired, the pipe according to the invention may have an external layer of fabric for protecting it against abrasion.

In United States application Serial No. 376,204 I have described a self-sealing petrol pipe embodying a helix of regenerated cellulose. This helix was located at the interior of the pipe and so exposed to the liquid flowing through the pipe. Regenerated cellulose however softens in water, and water is generally present in small quantities in petrol or oil. In the case of the pipe according to the invention, however, the regenerated cellulose is protected from the liquid and the pipe will moreover have the considerable advantage of a smooth bore.

One construction of pipe according to the invention will now be described in greater detail, by way of example, with reference to the accompanying drawing. The pipe has a, core I0, consisting of an extruded tube of polyvinyl chloride which is slipped on to a mandrel on which the pipe is built up.

Around the core is wound a layer Il of fabric,

coated on its inner surface with the cement sold under the British trade-mark Cellon-Linatex and rubberized on its outer surface. Around this is a helical winding I2 of regenerated cellulose wire. Surrounding this is a second layer I3 of fabric rubberized on both sides. Then comes a helix III of hemp cord or the like, the convolultions of which 'are` outl 'of register with those of the helix I2 of regenerated cellulose. Finally, there is an external layer I5 of fabric, rubberized on both sides and applied in overlapping windings. Preferably the rubber on all of the fabric layers is uncured, or only partially cured, the pipe being vulcanised after assembly, so' as to bond all the constituent layers securely together. yThe relativelto the core', and an external protective rubber on the outer surface of the external layer I5 of fabric may, however,be pre-vulcanised. As an alternative to bonding the layers by vulcanlsation of the rubber coatings applied to them, this may, if desired, be effected by the use of suitable rubber cements or plastic cements which will form abond Without curing.

`It is` important that al1 the layers should Ibe bonded together, and in particular that the fabric layers II, I3, should be bonded between the convolutions of regenerated cellulosel and Ahelix I2, lso as to prevent relative movement between the latter and the core I0. .It will be appreciated that the helix. I2y actsA asa stiffening for the whole pipe,4 and that unless the core I Ilwere bonded toitthe core would tend to collapse,` having very little natural strength. The cord Winding I I` assists to secure intimate bonding between the fabric layers II I3, makes the pipe stronger and assists it to bend when required. The lexternal layer I5 serves. as a protective lc overing. for protectingA the ypipe against abrasion, moisture and the effects of fluids spilt on the outside ofthe pipe.

Instead of using layers of fabric coatedwith rubber as described above, I may uselayers of fabric 4coated With polyvinyl chloride cement, thus producing a flexible pipe embodying-r no rubber at all in its construction. AThe constituent layers of the pipe Will be securely bonded together by the `polyvinyl chloride cement and an `external coating of polyvinyl chloride onthe outermost fabric layer I 5 will protect the pipe kagainst abrasion, moisture and the effectsof fluids spilt onit.

The new pipeislcapable of the most varied uses and will stand up to high temperatures. Thus itinaybe used as an ,oil hose for aircraft, lwhere covering bondedplto. said outer fabric layer.

2; A' flexible hose pipe, comprising a core consisting of an inner Atubular layer of a flexible synthetic material, an inner layer of fabric bonded to the core, a surrounding reinforcing helix of regenerated cellulose Wire, an outer fabric layer outside said helix and bonded to the inner fabric layer between the convolutions ithereof, a helix of cord around said outer fabric layer with itsconvolutions out of register with those of the helix of synthetic material, and an external protective covering bonded to said outer fabric layer. I 3.;A pipe as claimed in claim.2, in which the core, consists of polyvinyl chloride andthe constituentA layers of the pipe are bonded together by polyvinyl chloride cement.

4. A flexible hose pipe, comprising a core consisting of an inner tubular layerA of a flexible synthetic material, aninner layerof rubberized fabric bonded to the core,P a surrounding reinforcing helix, of regenerated celluloseA wire, an

outer ylayer of'rubberized fabric outside said helix and bondedv to the inner layerl between the convolutions thereof, a helix offcord surrounding theouter fabric layer and havingl its convolutionshout of register with those .Of the regenerated cellulose helix,v and an outer covering of rubberized cloth bonded to the outer fabric layer.

5. ,A flexible hose pipe, comprising a core con` sisting of anA innerptubular'layer of a flexible synthetic material, aninnerlayer of fabric bonded `to, the core, asurroundingv reinforcing helix of* regeneratedcellulose wire and an outer fabric layer outside said helix and .bonded to the inner fabric. ,layervr between the convolutions thereof,4 said inner` and Youter bondedV layers of fabricy holdingiheI reinforcing helix against movement relative tothe core. f

, BERNARD`WILK1NSON. 

